With developments of science and technology, there are more and more electronic devices, such as robots. It has been a trend to use the robots to do housework instead of human. For example, a cleaning robot can help people to clean the room by automatically moving itself and sucking up dusts on the floor without user operations.
When the cleaning robot begins to work, a cleaning task may be established. When the cleaning task is accomplished or an electric quantity is less than a preset value, the robot will go back to a charging port to charge itself.